1. Field of the Invention
The present embodiments discussed herein are related to a semiconductor device and a busbar.
2. Background of the Related Art
Semiconductor devices configured by connecting a plurality of semiconductor modules including IGBT (Insulated Gate Bipolar Transistors), FWD (Free Wheeling Diodes) and the like in parallel are in widespread use.
Although the semiconductor modules in such semiconductor devices are electrically connected in parallel, in an actual circuit, the length of wiring from the power supply may differ between modules. When the length of wiring differs between semiconductor modules that are connected in parallel, this will produce a difference in inductance. This means that a large surge voltage can be produced at a semiconductor module when the module is turned off. Switching failures can also occur due to differences in switching waveforms. For this reason, a proposed semiconductor device has pairs of semiconductor modules to be connected in parallel connected to busbars disposed in parallel so that the positive and negative terminals of the modules face one another (see, for example, Japanese Laid-open Patent Publication No. 2004-135444).
However, with the semiconductor device according to the cited document, when a plurality of pairs of semiconductor modules to be connected in parallel are connected to busbars so as to face one another, the distance from the power supply to a pair of semiconductor modules will differ to the distance from the power supply to another pair of semiconductor modules. Since the resistance of the busbar will also differ according to such difference in the distances, the current in each pair of semiconductor modules will also differ.